and 



t = K (V 2 + V 2 ) V 

 x x y 3 



r = K (V 2 + V 2 ) V 



y x y y 



(84) 



This constitutes the symmetric wind-stress field. The stress compo- 

 nents in the stretched shelf coordinate system are determined by 

 applying equation (84) in equations (47) and (48). 



The surface atmospheric pressure field associated with the hurri- 

 cane is given by: 



P = P +(P - P ) e " h , (85) 



o °° o 



where P Q is the central pressure and P ro is the far field pressure. 

 The term Hg in equations (40) and (41) is equivalent to 

 (P m - P)/p a g. 



The symmetric surface stress field does not reflect the influ- 

 ence of land. Without modeling this influence the analytically 

 determined wind field near the coast would not be consistent with that 

 from the NWS. A systematic procedure (App. H) is employed to alter 

 the symmetric wind field such that it portrays the effect of land. 

 These winds are referred to as deformed. Mr. Thomas Reid, Texas A&M 

 University, Department of Oceanography, is responsible for the basic 

 development of this wind model (unpublished manuscript) . The pressure 

 field was not altered in the nearshore region to conform with the 

 wind field. 



Figure 37(a) represents the symmetric Hurricane Carla wind field 

 at 1600 Greenwich mean time (G.m.t.), 11 September 1961 (approxi- 

 mately 4 hours before the storm crossed the coast) . Isovels are 

 shown in meters per second. The analytically deformed wind field at 

 this time is shown in Figure 37(b). The influence of land on the wind 

 field is evidence even at a time when the storm is approximately 55 

 kilometers from the coast. Figures 38 and 39 show the symmetric (a) 

 and deformed (b) winds at 2000 G.m.t., 11 September, and 0000 G.m.t., 

 12 September, respectively. The rotation and reduction of the wind 

 vector in the nearshore region to reflect the land influence is 

 illustrated in comparing Figure 40(a) for the symmetric case with 

 Figure 40(b) for the deformed wind. These figures correspond to the 

 contours shown in Figures 38(a) and 38(b), respectively. The arrows 

 represent the wind vector placed such that the tail is at the com- 

 putational point. The pressure fields, as determined from equation 

 (85) , for Hurricane Carla at the above times are shown in Figure 

 41(a,b,c) where the contours are in millibars. Although the pattern 

 of isovels reflecting the land influence is in good agreement with 



75 



